Dental implants are well known devices used in dental surgery to restore patients' lost, broken or decayed teeth. The essential function of a dental implant is to act as an anchor to hold in place a prosthetic device such as a fixed or removable denture appliance or single prosthetic tooth. Implants attain stability by being embedded in the patient's jawbone, thereby giving a firm foundation to the prosthetic device that protrudes above a patient's gum line.
Implants seen in the prior art have several disadvantages. First, to bring an implant procedure to completion requires several patient visits. Usually five to seven or more visits are necessary as well as possible referrals to specialists. The implant procedure itself requires surgery with flap and sutures leading to both significant patient discomfort, temporary restrictions on the types of food patients are permitted to eat, and a four to twelve month time period before the entire procedure is completed. In addition, there is a 10–15% failure rate. Failure of the procedure requires the use of alternative procedures over and above the failed implant surgery. Finally, the complete implant procedure, including the prosthetic device, can entail a high cost often out of the range of the average patient.
Typical of implants found in the prior art are those disclosed in U.S. Pat. Nos. 6,217,331 and 6,394,809 as well as United States Patent Application No. 2002/0142266, all to Rogers, et al. This series discloses a dental implant supporting a single prosthetic crown. The implant is described as having a threaded portion with a self-tapping region which allows insertion into the jawbone of a patient. The gingival portion is flared with a threaded bore that accepts a prosthetic device that extends above the gum line. The size of these implants mandate a waiting period of approximately 3–6 months before the prosthetic device is installed after the implant is first placed into the patient's jaw. This hold period allows ossification of the bone material around the inserted implant to ensure it is sufficiently secured in the bone structure. During this time, a flap is sewn over the implant to prevent infection during the ossification process. The required hold period delays the final installation of the dental prosthesis while the surgery can contribute to significant patient discomfort.
A similar implant is disclosed in United States Patent Application No. 2003/0068599 to Balfour, et al. The implant disclosed in the '599 application includes scalloped buccal and lingual portions that allow for tissue attachment to create a natural appearing gum line. However, the size of the implant disclosed in the '599 application necessitates the use of an insertion procedure that incorporates an extended waiting period to ensure sufficient ossification around the implant occurs.
Vigolo, et al. discloses the use of implants having a diameter in the range of 2.9 mm as supports for prosthetic crowns. [See The Journal of Prosthetic Dentistry, 84(1):50–54 (July 2000) which is hereby incorporated by reference in its entirety.] However, use of implants of this size still require a two month waiting period before a prosthesis can be attached to the implant. Similarly, U.S. Pat. No. 4,313,696 to Kasama, et al., which is hereby incorporated by reference in its entirety, discloses an implant supporting a single prosthetic crown. However, the '696 patent discloses that a period of wound healing must occur after the implant is placed in a patient's jaw. In addition, the device disclosed in the '696 patent includes an elastomeric cushion placed between the prosthetic crown and the implant.
The use of mini dental implants (MDIs) has been disclosed in U.S. Pat. No. 5,749,732 to Sendax, which patent is hereby incorporated by reference in its entirety. The '732 patent discloses an implant having a length of in the range of 17–19 mm, a threaded shaft diameter of about 1.8 mm with the threaded area having an unthreaded chord shaped section. Integral in the MDI of the '732 patent is an abutment end to which a dental prosthesis can be attached. The '732 patent discloses the use of the MDI to anchor a denture appliance holding a plurality of prosthetic teeth and requiring either a second MDI or another anchor such as a natural tooth to hold the denture. Also disclosed in the '732 patent is an implantation procedure for the MDI that eliminates the need for a surgical incision, flap and sutures, and the consequent ossification period before installing the dental prosthesis. However, the advantage of MDIs in enabling fast, relatively pain free insertion of dental prostheses is somewhat negated by their confinement to use with dentures supporting a plurality of artificial crowns and the need to use at least two anchors to support the denture.
Therefore, there exists in the field a need for a dental implant that can be used to securely support single dental crown prosthesis and that can be secured in a patient's jawbone using a procedure that reduces the time to complete installation of the prosthesis and patient discomfort and pain.